\documentclass[border=5mm]{standalone}
\usepackage{tikz}
\usepackage{tikz-qtree}

\begin{document}
\begin{tikzpicture}[every tree node/.style={align=center}]
    \matrix[row sep=1cm, column sep=1cm] {
    \Tree
    [.\node[draw, circle]{8};
    [.\node[draw, circle]{4};
    [.\node[draw, circle]{\textcolor{red}{1}}; ]
    [.\node[draw, rectangle]{6 7}; ]
    ]
    [.\node[draw, rectangle]{12 14};
    [.\node[draw, rectangle]{9 10}; ]
    [.\node[draw, circle]{13}; ]
    [.\node[draw, circle]{15}; ]
    ]
    ];
    &
    \Tree
    [.\node[draw, circle]{8};
    [.\node[draw, fill=yellow, circle]{6};
    [.\node[draw, fill=yellow, circle]{4}; ]
    [.\node[draw, fill=yellow, circle]{7}; ]
    ]
    [.\node[draw, rectangle]{12 14};
    [.\node[draw, rectangle]{9 10}; ]
    [.\node[draw, circle]{13}; ]
    [.\node[draw, circle]{15}; ]
    ]
    ]; \\
    };
\end{tikzpicture}
\end{document}
